Insulation Bobbin of a Stator

ABSTRACT

An insulation bobbin of a stator includes a body and a plurality of extension members. The body has an assembly hole and the extension members are coupled to the body. Each of the extension members has a wound portion. The wound portion has a top plate and two side walls located on two sides of the top plate. A thickness of the top plate is smaller than that of the two side walls.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an insulation bobbin of astator and, more particularly, to an insulation bobbin of a stator thatprovides a larger room for radial windings.

2. Description of the Related Art

Referring to FIG. 1, Taiwanese Patent No. 525869 discloses aconventional insulation bobbin 9 of a stator of a DC motor. Theinsulation bobbin 9 includes a body 91 and a plurality of extensionmembers 92. The body 91 includes a hole 911 from which the extensionmembers 92 extend outwards radially. Each extension member 92 has anaccommodation room 921 whose cross section resembles a “□” shape. Theaccommodation room 921 has an opening and two protruding clamp 922located on two edges of the opening.

When the insulation bobbin 9 is coupled with a silicon steel plate unit8, the accommodation rooms 921 may accommodate a plurality ofsalient-poles 81 of the silicon steel plate unit 8, in which a pluralityof pole faces 82 of the silicon steel plate unit 8 extends outside theaccommodation rooms 921. Based on this, each protruding clamp 922 mayhave a top face abutting against a bottom face of an individualsalient-pole 81 so that a bottom face of the protruding clamp 922 isspaced from the bottom face of the salient-poles 81 by a distance. Withthe distance, a metallic coil C can be kept away from the salient-poles81 during the winding process.

In general, when the extension members 92 are wound with more turns ofthe metallic coil C, the DC motor will have stronger magnetic fields andlarger rotation torque. In order to improve the structural strength ofthe insulation bobbin 9, the portion of the extension member 92 aroundwhich the metallic coil C is wound usually has the same thickness T. Asa result, less turns of the metallic coil C can be wound around theextension members 92 in an axial direction of the DC motor. In light ofthis problem, the thickness of the extension member 92 may be reduced toincrease the number of turns of the metallic coil C. However, thisreduces the structural strength of the extension members 92, causing theextension members 92 to be easily damaged during assembling and windingprocesses.

Therefore, it is desired to improve the conventional insulation bobbin9.

SUMMARY OF THE INVENTION

It is therefore the primary objective of this invention to overcome theabove conventional insulation bobbin by providing an insulation bobbinof a stator that has a larger room for radial windings.

The invention discloses an insulation bobbin of a stator includes a bodyand a plurality of extension members. The body has an assembly hole andthe extension members are coupled to the body. Each of the extensionmembers has a wound portion. The wound portion has a top plate and twoside walls located on two sides of the top plate. A thickness of the topplate is smaller than that of the two side walls.

Furthermore, the invention discloses an insulation bobbin unit of astator including a first insulation bobbin and a second insulationbobbin. The first insulation bobbin has a first body and a plurality offirst extension members coupled with the first body. The first body hasa first assembly hole. Each of the extension members has a first woundportion. The first wound portion has a first top plate and at least onefirst side wall located on two sides of the top plate. A thickness ofthe first top plate is smaller than that of the at least one first sidewall. The second insulation bobbin has a second body and a plurality ofsecond extension members. The second body is coupled with the first bodyand has a second assembly hole aligning and communicating with the firstassembly hole. The second extension members are coupled with the secondbody and aligned with the first extension members. Each of the secondextension members has a second wound portion. The second wound portionhas a second top plate and at least one second side wall located on twosides of the top plate. A room is defined by the first top plate, thefirst side wall, the second top plate and the second side wall.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinafter and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 shows a silicon steel plate unit and a conventional insulationbobbin.

FIG. 2 shows a side cross sectional view of the silicon steel plate unitfitted into the conventional insulation bobbin.

FIG. 3 shows a silicon steel plate unit and an insulation bobbinaccording to a first embodiment of the invention.

FIG. 4 shows a side cross sectional view of the silicon steel plate unitfitted into the insulation bobbin according to the first embodiment ofthe invention.

FIG. 5 shows a silicon steel plate unit and two insulation bobbinsaccording to a second embodiment of the invention.

FIG. 6 shows a side cross sectional view of the silicon steel plate unitsandwiched between the two insulation bobbins according to the secondembodiment of the invention.

FIG. 7 shows a silicon steel plate unit and two insulation bobbinsaccording to a third embodiment of the invention.

In the various figures of the drawings, the same numerals designate thesame or similar parts. Furthermore, when the term “first”, “second”,“third”, “fourth”, “inner”, “outer” “top”, “bottom” and similar termsare used hereinafter, it should be understood that these terms referonly to the structure shown in the drawings as it would appear to aperson viewing the drawings and are utilized only to facilitatedescribing the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 3 and 4, a single insulation bobbin of a stator of amotor is shown according to a first embodiment of the invention. Theinsulation bobbin includes a body 1 and a plurality of extension members2. The extension members 2, with equal distance, may be formed on anouter wall of the body 1 in an integral manner.

The body 1 is made of insulation material such as plastic. The body 1has an assembly hole 11 extending in an axial direction so that theinsulation bobbin may be fitted through the assembly hole 11 onto anouter circumferential wall of a bearing of the motor.

Each extension member 2 has a connection end 21, a free end 22, a woundportion 23, an accommodation room 24, two stop walls 25 and a standingwall 26. The connection end 21 and the free end 22 are respectivelylocated on two ends of the extension member 2. The connection end 21 isconnected to the body 1. The free end 22 has a wider width than theconnection end 21 so that the extension member 2 resembles a “T” shapefrom a top view. There is a gap between two adjacent free ends 22 forwinding purposes. The wound portion 23 is located between the connectionend 21 and the free end 22 and consists of a top plate 231 and two sidewalls 232. The top plate 231 extends from the connection end 21 to thefree end 22. The two side walls 232 extend downwards from two sides ofthe top plate 231 so that the cross section of the extension member 2resembles a “□” shape. Each side wall 232 has an engaging hook 233 onone end not connecting to the top plate 231. In particular, referring toFIG. 4, a distance between outer and inner faces of the top plate 231 isthe thickness T1 of the top plate 231, whereas a distance between outerand inner faces of the side wall 232 is the thickness T2 of the sidewall 232. The thickness T1 of the top plate 231 is smaller than thethickness T2 of the side wall 232.

Referring to FIG. 3 again, the accommodation room 24 is surrounded bythe top plate 231 and the two side walls 232. The two stop walls 25 arelocated under the free end 22 and the standing wall 26 is located abovethe free end 22. The two stop walls 25 are connected to the two sidewalls 232.

Referring to FIGS. 3 and 4 again, during usage of the insulation bobbin,a plurality of salient-poles 71 of a silicon steel plate unit 7 isreceived in the accommodation rooms 24 of the extension members 2, inwhich each engaging hook 233 abuts against a bottom face of anindividual salient-pole 71 to support and position the silicon steelplate unit 7. In addition, the silicon steel plate unit 7 furtherincludes a plurality of pole faces 72 extending outside the stop walls25. Based on this, the wound portion 23 of each extension member 2 iswound with a metallic coil C. The metallic coil C may be fixed to andpositioned at the extension member 2 through the two stop walls 25 andthe standing wall 26. The wound portion 23 is wound with the metalliccoil C until a predetermined axial winding height H is reached, thusaccomplishing the winding process of the motor.

Referring to FIGS. 2 and 4, the insulation bobbin of the firstembodiment of the invention is characterized by that the wound portion23, based on the same predetermined axial winding height H as theextension member 92 of the conventional insulation bobbin 9, may bewound with more turns of the metallic coil C in the axial direction byhaving the thickness T1 of the top plate 231 smaller than the thicknessT2 of the side wall 232. In addition, the structural strength of theextension member 2 may still be maintained by having the thickness T2 ofthe side wall 232 larger than the thickness T1 of the top plate 231.Thus, the insulation bobbin of the invention may provide a larger roomfor radial windings. In addition, when the insulation bobbin is appliedto a motor, the motor may have stronger magnetic fields to producestronger rotation torque for the motor.

Referring to FIGS. 5 and 6, an insulation bobbin unit of a stator isdisclosed according to a second embodiment of the invention. Incomparison with the first embodiment, the insulation bobbin unit of thesecond embodiment consists of a first insulation bobbin and a secondinsulation bobbin. The first and second insulation bobbins aresubstantially similar to that of the first embodiment. That is, the body1, assembly hole 11, extension members 2, connection end 21, free end22, wound portion 23, top plate 231, side walls 232, accommodation room24, stop walls 25 and standing wall 26 of the insulation bobbin of thefirst embodiment correspond to a first body 1′, a first assembly hole11′, a plurality of first extension members 2′, a first connection end21′, a first free end 22′, a first wound portion 23′, a first top plate231′, two first side walls 232′, a first accommodation room 24′, twofirst stop walls 25′ and a first standing wall 26′ of the firstinsulation bobbin of the second embodiment, as well as a second body 1″,a second assembly hole 11″, a plurality of second extension members 2″,a second connection end 21″, a second free end 22″, a second woundportion 23″, a second top plate 231″, two second side walls 232″, asecond accommodation room 24″, two second stop walls 25″ and a secondstanding wall 26″ of the second insulation bobbin of the secondembodiment. The details of the first and second insulation bobbins arenot described herein again for brevity.

In the second embodiment, the first body 1′ may be aligned and coupledwith the second body 1″ to allow communication between the firstassembly hole 11′ and the second assembly hole 11″. Based on this, thefirst and second insulation bobbins may be fitted onto a circumferentialwall of a bearing of the motor through the first assembly hole 11′ andthe second assembly hole 11″. In addition, the first extension members2′ may be aligned and coupled with the second extension members 2″ toallow communication between the first accommodation room 24′ and thesecond accommodation room 24″, in which bottom faces of the two firststop walls 25′ abut against top faces of the two second stop walls 25″.

Particularly, referring to FIG. 6, taking the first wound portion 23′and the second wound portion 23″ as an example, a thickness T3 of thefirst top plate 231′ may be smaller than a thickness T4 of the firstside wall 232′, or a thickness T5 of the second top plate 231″ may besmaller than a thickness T6 of the second side wall 232″. In thisembodiment, both the thicknesses T3 and T5 of the first top plate 231′and the second top plate 231″ are respectively smaller than thethicknesses T4 and T6 of the first side wall 232′ and the second sidewall 232″, with the thickness T4 of the first side wall 232′ being equalto the thickness T6 of the second side wall 232″.

Referring to FIGS. 5 and 6, during usage of the first and secondinsulation bobbins, the silicon steel plate unit 7 is sandwiched betweenthe first and second insulation bobbins, allowing the salient-poles 71to be received in a space formed by the first accommodation room 24′ andthe second accommodation room 24″, as well as allowing the pole faces 72to extend outside the two first stop walls 25′ and the two second stopwalls 25″. Finally, the first wound portion 23′ and the second woundportion 23″ are respectively wound with the metallic coil C to completethe winding processes.

The second embodiment of the invention differs from the first embodimentin that the silicon steel plate unit 7 in the second embodiment, beforebeing wound with the metallic coil C, is sandwiched between twoinsulation bobbins (the first and second insulation bobbins) rather thanonly a single insulation bobbin as disclosed in the first embodiment.Based on this, with the same axial winding height H of the first woundportion 23′ and the second wound portion 23″, the thicknesses T3 and T5of the first top plate 231′ and the second top plate 231″ are madesmaller than the thicknesses T4 and T6 of the first side wall 232′ andthe second side wall 232″, so that the first wound portion 23′ and thesecond wound portion 23″ may be wound with more turns of the metalliccoil C in the axial direction. Therefore, stronger magnetic fields maybe generated. Furthermore, the first and second insulation bobbins ofthe embodiment may further prevent electrical connection between themetallic coil C and the silicon steel plate unit 7 for better insulationeffect.

Referring to FIG. 7, two insulation bobbins are disclosed according to athird embodiment of the invention. In comparison with the secondembodiment, the first wound portion 23′ consists of a first top plate231′ and a first side wall 232′, and the second wound portion 23″consists of a second top plate 231″ and a second side wall 232″. Basedon this, the first extension members 2′ and the second extension members2″ of the embodiment appear to be an “L” shape in their cross sections.Thus, when the first body 1′ is aligned and coupled with the second body1″, the first side wall 232′ may abut against an edge of the second topplate 231″ that is not mounted with the second side wall 232″.Similarly, the second side wall 232″ may abut against an edge of thefirst top plate 231′ that is not mounted with the first side wall 232′.Therefore, communication between the first accommodation room 24′ andthe second accommodation room 24″ is allowed. Thus, the silicon steelplate unit 7 may be jointly encased by the first top plate 231′, firstside wall 232′, second top plate 231″ and the second side wall 232″.

In particular, the thickness of the first top plate 231′ may be smallerthan that of the first side wall 232′. Alternatively, the thickness ofthe second top plate 231″ may be smaller than that of the second sidewall 232″. In this embodiment, the thicknesses of the first top plate231′ and the second top plate 231″ are smaller than those of the firstside wall 232′ and the second side wall 232″, respectively.

Based on this, the first wound portion 23′ and the second wound portion23″ may have more turns of winding on the axial direction, therebyproviding stronger magnetic fields and better insulation effect.

Although the invention has been described in detail with reference toits presently preferable embodiment, it will be understood by one ofordinary skill in the art that various modifications can be made withoutdeparting from the spirit and the scope of the invention, as set forthin the appended claims.

1. An insulation bobbin of a stator, comprising: a body having anassembly hole; and a plurality of extension members coupled to the body,wherein each of the extension members has a wound portion, the woundportion has a top plate and two side walls located on two sides of thetop plate, and a thickness of the top plate is smaller than that of thetwo side walls.
 2. The insulation bobbin of the stator as claimed inclaim 1, wherein each of the extension members has two stop wallsconnected to the two side walls and formed on one end of the top platethat is not connected to the body.
 3. The insulation bobbin of thestator as claimed in claim 1, wherein each of the extension members hasa standing wall formed on one end of the top plate that is not connectedto the body.
 4. The insulation bobbin of the stator as claimed in claim1, wherein the wound portion has an engaging hook formed on one end ofeach of the two side walls that is not connected to the top plate.
 5. Aninsulation bobbin unit of a stator, comprising: a first insulationbobbin having a first body and a plurality of first extension memberscoupled with the first body, wherein the first body has a first assemblyhole, each of the extension members has a first wound portion, the firstwound portion has a first top plate and one first side wall located onone side of the first top plate, and a thickness of the first top plateis smaller than that of the first side wall; and a second insulationbobbin having a second body and a plurality of second extension members,wherein the second body is coupled with the first body and has a secondassembly hole aligning and communicating with the first assembly hole,the second extension members are coupled with the second body andaligned with the first extension members, each of the second extensionmembers has a second wound portion, the second wound portion has asecond top plate and one second side wall located on one side of thesecond top plate, and a room is defined by the first top plate, thefirst side wall, the second top plate and the second side wall.
 6. Theinsulation bobbin unit of the stator as claimed in claim 5, wherein athickness of the second top plate is smaller than that of the at leastone second side wall.
 7. The insulation bobbin unit of the stator asclaimed in claim 5, wherein the first wound portion has the other firstside wall and the second wound portion has the other second side wall,the two first side walls are located on two sides of the first top plateand the two second side walls are located on two sides of the second topplate, and the two second side walls are aligned with the two first sidewalls.
 8. The insulation bobbin unit of the stator as claimed in claim5, wherein the first side wall is aligned with one edge of the secondtop plate that is not mounted with the second side wall, and the secondside wall is aligned with one edge of the first top plate that is notmounted with the first side wall.
 9. The insulation bobbin unit of thestator as claimed in claim 5, wherein each of the first extensionmembers includes one first stop wall and a first standing wall, thefirst stop wall and the first standing wall are formed on one end of thefirst top plate that is not connected to the first body, the first stopwall is located under the first top plate, the first standing wall islocated above the first top plate, and the first stop wall is connectedto the first side wall.
 10. The insulation bobbin unit of the stator asclaimed in claim 9, wherein each of the second extension membersincludes one second stop wall and a second standing wall, the secondstop wall and the second standing wall are formed on one end of thesecond top plate that is not connected to the second body, the secondstop wall is located under the second top plate, the second standingwall is located above the second top plate, and the second stop wall isconnected to the second side wall.
 11. The insulation bobbin unit of thestator as claimed in claim 10, wherein the first wound portion has theother first side wall located on the other side of the first top plate,and the second wound portion has the other second side wall located onthe other side of the second top plate, each of the first extensionmembers includes the other first stop wall formed on the end of thefirst top plate that is not connected to the first body, the other firststop wall is located under the first top plate and is connected to theother first side wall, each of the second extension members includes theother second stop wall formed on the end of the second top plate that isnot connected to the second body, and the other second stop wall islocated under the second top plate and is connected to the other secondside wall.